Sun Also Rises On Solar Homes

Energy Source Cuts Electric Need

March 30, 2001|By Mary Beth Breckenridge, Knight Ridder/Tribune.

Gary Cole's house probably isn't what you'd envision as a solar home.

The substantial front porch and fish-scale siding root the house more firmly in 1910 than 2001--until, that is, you spot the attic window. It's shaded by what appears at first glance to be a shutter but is really a pair of solar panels, the power source for a generating system that provides a small part of Cole's electrical needs.

There are no unwieldy structures jutting up from the roof, no eyesore contraptions to make the house stick out from the others in this comfortable old neighborhood on Cleveland's west side. "My neighbors thought it was a new window," Cole says of the solar setup. "Nobody really noticed it."

Solar-powered homes are few and the generating systems relatively expensive in areas that don't get a great deal of sun year-round. Cole and other environmentally conscious homeowners, however, are so convinced of the benefits of solar power that they're willing to put their money where their convictions are.

The idea behind solar power isn't to replace conventional energy sources such as electricity and natural gas, but rather to reduce the need for them, says William Spratley, director of Green Energy Ohio, an organization that promotes environmentally friendly energy sources.

"This is not a panacea," he says. Nevertheless, Spratley and other advocates of solar energy say it's a renewable, nonpolluting way to reduce America's dependence on fossil fuels. In an era of rising energy costs, though, they believe it eventually could become an economically viable one.

Photovoltaic systems such as Cole's, which turn the sun's radiation into electricity, are just one of the ways sunlight is captured for residential use, says Maureen McIntyre, editor and publisher of Solar Today, a magazine published by the American Solar Energy Society. Other methods include passive solar systems, which use the sun's warmth and light to heat and brighten homes without mechanical help, and solar hot-water systems, which use the sun to heat water. Active solar systems that use mechanical means to capture the sun's warmth for heating homes have fallen out of favor as too expensive and inefficient, McIntyre says.

Photovoltaic generation is the most expensive of the currently popular solar options, she says, "but it's also the sexiest."

A photovoltaic system operates on the same technology as a solar-powered calculator. The basic element of the system is the photovoltaic cell, which is made of silicon. When the silicon in the cell absorbs sunlight, electrons within it become agitated and move through the silicon, producing electricity.

Photovoltaic cells have been around since the 1950s, but their reliability and efficiency have improved greatly in recent years. According to the U.S. Department of Energy's National Renewable Energy Laboratory, today's cells are about 15 percent efficient, meaning about one-sixth of the sunlight striking the cells generates electricity. The earliest cells had efficiencies of less than 4 percent.

Still, solar advocates say the cells need to become even more efficient to make photovoltaic systems economical. A typical system costs $10,000 to $20,000, Spratley says, putting it out of most people's reach. "The biggest barrier is that we're trying to get the price down," he says.

Photovoltaic cells, typically grouped in solar panels, are sometimes mounted on roofs and sometimes on the ground. They even come in the form of solar shingles, which are shaped like regular asbestos shingles and are used to cover part or all of a roof.

United Solar Systems Corp. of Troy, Mich., won awards from Popular Science and Discover magazines for its Uni-Solar shingles, which are made of amorphous silicon rather than glass, so they're flexible and unbreakable, says company spokeswoman Angela Palmieri. They have a rubbery flap that's nailed in place just like an asbestos shingle and wires that are fed through holes in the roof to components inside the house.

In Cole's system, the electricity that his solar panels produce is stored in four batteries in his basement, which power his home office and the electronic equipment in his living room entertainment center. A device called an inverter changes the electricity from direct current to alternating current so it can be used by common household appliances and devices.

The photovoltaic system generates more power in summer, less in winter. If he uses up the power from the batteries, electricity supplied by FirstEnergy takes over.

Averaged over the year, Cole's two panels produce about 1 kilowatt-hour (kwh) a day, about one-fifteenth of the power he needs. He intends, however, to add enough panels this summer to produce an average of 16 kwh a day--an amount worth about $700 a year, based on FirstEnergy's current rate.

That means it would take him 20 years to recoup the $14,000 cost of the expanded system. He's counting on electrical rates increasing, however, which would make the payback time shorter.